Dissolved organic carbon(DOC)is a mixture of organic compounds with varying molecular sizes and weights.In forest ecosystems,litterfall is a major aboveground resource of DOC,which supplies soils with carbon as a crucial component of terrestrial biogeochemical cycles.During the migration of litterfall-derived DOC from topsoils to subsoils,soils might retain,transform,or release DOC,depending on the chemical nature of DOC and its interactions with soil surfaces.These physicochemical processes contribute cons...